I am wondering if someone can assist me with making the below script work with a 3-tier expand/collapse menu?

50Webs Tutorials » Expand-Collapse Menu

Right now, it's only programmed for 2-tiers. I need to be able to expand like this:

+ Item
...+ Item
......- Item
......- Item

Here it is in practice: Expanding Menu

If you expand Direct Lending you'll see that Industry Verticals opens already expanded and can't be closed.

Thanks in advance for any help.